#include <stdio.h>
long fun(int m)
{
    switch(m) /******found******/
    {  
        case 0: return 0;
        /******found******/
        case 1: case 2: return 1 ; 
    }
    return fun(m-1) + fun(m-2) ;  /******found******/
}
void main()
{  
    long fib; 
    int n;
    scanf("%d",&n);
    printf("n = %d\n",n);
    fib = fun(n);
    printf("fib = %ld\n",fib);  /******found******/
}
